SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF SODIUM VANADYL(IV) ORTHOPHOSPHATE NAVOPO4

Abstract

A new sodium vanadyl(IV) orthophosphate NaVOPO4 has been synthesized by solid-state and hydrothermal method and characterized by single-crystal X-ray diffraction and magnetic susceptibility. It crystallizes in the monoclinic space group P2(1)/c with a = 6.524(1), b = 8.455(4), c = 7.119(1), beta = 115.29(1)-degrees, Z = 4, R = 0.027, and is structurally similar to the triclinic analog LiVOPO4. The structure can be described as close-packed infinite chains of trans-corner-sharing VO6 octahedra with the holes around each chain filled with Na and P atoms. These infinite chains have alternating short and long V - O bonds and are similar to those found in beta-VOPO4. The Na atom has six close oxygen neighbors at distances of 2.268 to 2.511 angstrom.